Solar-powered airplane nears end of around-the-world journey

The crew of the Solar Impulse 2 began their next-to-last leg of the solar airplane's global journey today. The plane left Seville, Spain, at around dawn local time on Monday. The team behind the project expects the plane to land in Cairo, Egypt, after 50 hours and 30 minutes of flying, according to the Solar Impulse 2's website, where you can follow the plane's journey.

The goal of the Solar Impulse 2's around-the-world flight is to show the potential of solar technology. The 5,500-pound plane travels at about 47 miles per hour, propelled not by fossil fuels, but rather by 17,248 solar cells on the wings, which convert sunlight into electricity to power the four electric engines and propellers.